如何删除 webrtc sdp 中的视频编解码器？

Question

我想知道如何从 SDP 报价中删除 H264 编解码器。或者我可以以某种方式禁用此编解码器？我找到了一个非常好的解决方案，但我收到错误。行

出现错误

var modsdp = sdp.replace(codecre, "");

Uncaught SyntaxError: Invalid or unexpected token

function removeCodec(orgsdp, codec) {
var internalFunc = function(sdp) {
    var codecre = new RegExp('(a=rtpmap:(\d*) ' + codec + '\/90000\r\n)');
    var rtpmaps = sdp.match(codecre);
    if (rtpmaps == null || rtpmaps.length <= 2) {
        return sdp;
    }
    var rtpmap = rtpmaps[2];
    var modsdp = sdp.replace(codecre, "");
    var rtcpre = new RegExp('(a=rtcp-fb:' + rtpmap + '.*\r\n)', 'g');
    modsdp = modsdp.replace(rtcpre, "");
    var fmtpre = new RegExp('(a=fmtp:' + rtpmap + '.*\r\n)', 'g');
    modsdp = modsdp.replace(fmtpre, "");
    var aptpre = new RegExp('(a=fmtp:(\d*) apt=' + rtpmap + '\r\n)');
    var aptmaps = modsdp.match(aptpre);
    var fmtpmap = "";
    if (aptmaps != null && aptmaps.length >= 3) {
        fmtpmap = aptmaps[2];
        modsdp = modsdp.replace(aptpre, "");
        var rtppre = new RegExp('(a=rtpmap:' + fmtpmap + '.*\r\n)', 'g');
        modsdp = modsdp.replace(rtppre, "");
    }
    var videore = /(m=video.*\r\n)/;
    var videolines = modsdp.match(videore);
    if (videolines != null) {
        //If many m=video are found in SDP, this program doesn't work.
        var videoline = videolines[0].substring(0, videolines[0].length - 2);
        var videoelem = videoline.split(" ");
        var modvideoline = videoelem[0];
        for (var i = 1; i < videoelem.length; i++) {
            if (videoelem[i] == rtpmap || videoelem[i] == fmtpmap) {
                continue;
            }
            modvideoline += " " + videoelem[i];
        }
        modvideoline += "\r\n";
        modsdp = modsdp.replace(videore, modvideoline);
    }
    return internalFunc(modsdp);
};
return internalFunc(orgsdp);}

感谢您的帮助。

Answer 1

我在此处收到的答案 https://groups.google.com/forum/#!topic/discuss-webrtc/4lNUw9CkhIc 工作正常。只需要重写几行代码（已注释掉）。他们看起来一样。但是注释掉的行会导致语法错误。我猜他们是用不同于英语的语言写的。在英文键盘上重写它们解决了问题

function removeCodec(orgsdp, codec) {
var internalFunc = function(sdp) {
    var codecre = new RegExp('(a=rtpmap:(\d*) ' + codec + '\/90000\r\n)');
    var rtpmaps = sdp.match(codecre);
    if (rtpmaps == null || rtpmaps.length <= 2) {
        return sdp;
    }
    var rtpmap = rtpmaps[2];
    // var modsdp = sdp.replace(codecre, "");
    var modsdp = sdp.replace(codecre, "");
    var rtcpre = new RegExp('(a=rtcp-fb:' + rtpmap + '.*\r\n)', 'g');
    //  modsdp = modsdp.replace(rtcpre, "");
    modsdp = modsdp.replace(rtcpre, "");
    var fmtpre = new RegExp('(a=fmtp:' + rtpmap + '.*\r\n)', 'g');
    //    modsdp = modsdp.replace(fmtpre, "");
    modsdp = modsdp.replace(fmtpre, "");
    var aptpre = new RegExp('(a=fmtp:(\d*) apt=' + rtpmap + '\r\n)');
    var aptmaps = modsdp.match(aptpre);
    var fmtpmap = "";
    if (aptmaps != null && aptmaps.length >= 3) {
        fmtpmap = aptmaps[2];
        // modsdp = modsdp.replace(aptpre, "");
        modsdp = modsdp.replace(aptpre, "");
        var rtppre = new RegExp('(a=rtpmap:' + fmtpmap + '.*\r\n)', 'g');
        modsdp = modsdp.replace(rtppre, "");
    }
    var videore = /(m=video.*\r\n)/;
    var videolines = modsdp.match(videore);
    if (videolines != null) {
        //If many m=video are found in SDP, this program doesn't work.
        var videoline = videolines[0].substring(0, videolines[0].length - 2);
        var videoelem = videoline.split(" ");
        var modvideoline = videoelem[0];
        for (var i = 1; i < videoelem.length; i++) {
            if (videoelem[i] == rtpmap || videoelem[i] == fmtpmap) {
                continue;
            }
            modvideoline += " " + videoelem[i];
        }
        modvideoline += "\r\n";
        modsdp = modsdp.replace(videore, modvideoline);
    }
    return internalFunc(modsdp);
};
return internalFunc(orgsdp);

}

如何删除 webrtc sdp 中的视频编解码器？

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